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Webbrowser control's window.external is ALWAYS null

由 断了今生、忘了曾经 提交于 2019-12-20 03:09:56
问题 The Web browser's Window.External object is always null! To reproduce drop a web browser on a new winform and type: Option Strict Off Public Class Form1 Private Sub Form1_Load() Handles MyBase.LoadMe.WebBrowser1.Document.Window.DomWindow.External.AddFavorite("http://www.google.com") End Sub End Class Make certain you go to the Assembly Information dialog and check "Make Assembly COM-Visible." This is necessary. I am lost as to why with a COM visible assembly the External object is always

Set variables to “Nothing” is a good practice?

由 拟墨画扇 提交于 2019-12-19 09:15:13
问题 If I got Dim myRect As Rectangle = New Rectangle(0,0,100,100) Is it necessary or just fine to later do this: myRect = Nothing Or it isn't necessary? Thank you. IF it is necessary, are there other cases it isn't for my variables? 回答1: In general, as Joel said, it's unnecessary. In your specific example, though, it is actually pointless . Rectangle is a value type , so setting it to Nothing is not even affecting an object's reference count; it's assigning a new value (the default value for

Still have error “value copy is not a member of Nothing” even I filter Nothing class

由 狂风中的少年 提交于 2019-12-11 08:35:24
问题 I use scala 2.11.2. This is part of my function: import scala.reflect.runtime.universe._ p => p.filter(p => typeOf[p.type] != typeOf[Nothing]).flatMap { case Some(profile) => { ... env.userService.save(profile.copy(passwordInfo = Some(hashed)),...) //<---------error here } case _ => ... } the compile error is： PasswordReset.scala:120: value copy is not a member of Nothing [error] env.userService.save(profile.copy(passwordI nfo = Some(hashed)), SaveMode.PasswordChange); [error] ^ I think I use

VB.Net Linq to Entities Null Comparison - 'Is Nothing' or '= Nothing'?

由 非 Y 不嫁゛ 提交于 2019-12-10 14:56:47
问题 We have several projects in VB.Net, using .Net Framework 4 and Linq to Entities for many of our SQL queries. Moving to EF is a new shift for us (been using it for about 4-6 months) and has the backing of upper management because we can code so much faster. We still use a lot of stored procs, but we even execute those through Linq to Entities as well. I'm hoping to clear some confusion up and I can't find a direct answer that makes sense. We have some queries where we want records where a

Webbrowser control's window.external is ALWAYS null

由 ≯℡__Kan透↙ 提交于 2019-12-02 01:17:38
The Web browser's Window.External object is always null! To reproduce drop a web browser on a new winform and type: Option Strict Off Public Class Form1 Private Sub Form1_Load() Handles MyBase.LoadMe.WebBrowser1.Document.Window.DomWindow.External.AddFavorite("http://www.google.com") End Sub End Class Make certain you go to the Assembly Information dialog and check "Make Assembly COM-Visible." This is necessary. I am lost as to why with a COM visible assembly the External object is always nothing. Have you set the ObjectForScripting property to your host window? I think you need to do that for

Why does map/filter … not work with an Array of Nothing?

由 不打扰是莪最后的温柔 提交于 2019-12-01 09:25:19
Isn't Nothing a subtype of all types? scala> val array = new Array(5) array: Array[Nothing] = Array(null, null, null, null, null) scala> array.map(_ => 42) <console>:9: error: value map is not a member of Array[Nothing] array.map(_ => 42) ^ scala> array.filter(_ != 42) <console>:9: error: value filter is not a member of Array[Nothing] array.filter(_ != 42) ^ It's weird that this doesn't work. Is this specified, a feature or a bug? When you see weird behavior involving Nothing, it's because the type inference algorithm thinks that it inserted Nothing itself, since it is introduced during type

Why does map/filter … not work with an Array of Nothing?

由 霸气de小男生 提交于 2019-12-01 07:10:21
问题 Isn't Nothing a subtype of all types? scala> val array = new Array(5) array: Array[Nothing] = Array(null, null, null, null, null) scala> array.map(_ => 42) <console>:9: error: value map is not a member of Array[Nothing] array.map(_ => 42) ^ scala> array.filter(_ != 42) <console>:9: error: value filter is not a member of Array[Nothing] array.filter(_ != 42) ^ It's weird that this doesn't work. Is this specified, a feature or a bug? 回答1: When you see weird behavior involving Nothing, it's

C# vs VB.NET - Handling of null Structures

由 爱⌒轻易说出口 提交于 2019-11-29 16:20:45
问题 I ran across this and was wondering if someone could explain why this works in VB.NET when I would expect it should fail, just like it does in C# //The C# Version struct Person { public string name; } ... Person someone = null; //Nope! Can't do that!! Person? someoneElse = null; //No problem, just like expected But then in VB.NET... Structure Person Public name As String End Structure ... Dim someone As Person = Nothing 'Wha? this is okay? Is Nothing not the same as null ( Nothing != null -

Using Haskell's “Maybe”, type declarations [beginner's question]

由 ⅰ亾dé卋堺 提交于 2019-11-29 10:43:51
I've started experimenting with Haskell and have a problem. qqq is a function that should print one string if called with "Nothing" and print other things if called with "Just something". The first attempt seems like working: qqq Nothing = print "There isn't anything to be printed." qqq (Just x) = print "There is something to be printed." >> print x main :: IO () main = qqq (Just 43) But: when I try to make main = qqq (Nothing) it fails ("Ambiguous type variable `a0' in the constraint: (Show a0) arising from a use of 'qqq'") When I want to add type signature if fails: qqq :: Maybe x => x -> IO

VBA: Conditional - Is Nothing

由 非 Y 不嫁゛ 提交于 2019-11-29 05:31:43
There is an If condition in a VBA application as seen below: If Not My_Object Is Nothing Then My_Object.Compute When the code is run in debug mode, I found that the If condition returns a true even when My_Object has "No Variables". Could somebody please explain this? I want My_Object.Compute to be executed only when My_Object exists. Based on your comment to Issun: Thanks for the explanation. In my case, The object is declared and created prior to the If condition. So, How do I use If condition to check for < No Variables> ? In other words, I do not want to execute My_Object.Compute if My
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